Machine-driven selector



April 30, 1929.

H. W. R. THORELLI MACHINE DRIVEN SELECTOR Filed May 25, 1928 W E Wo d 1' switching apparatus Patented Apr. 30, 1929.

UNITED STATES PATENT OFFICE.

HANS WILHELM ROBERT THO FONAKTIEBOLAGET SWEDEN.

Application filed L. M. EBICSSON,

RELLI, 0F NORRVIKEN, SWEDEN, ASSIGNOR TO TELE- OF STOCKHOLM, SWEDEN, A. COMPANYOF MACHINE-DRIVEN SELECTOR.

May 23, 1928, Serial No. 280,040, and in Sweden May 30, 1927.

The invention relates to such machine driven selectors for autmnatic telephone systems which are set under the control o't an vided for said purpose sender actuated by the mechanism of the select impulses to impulse reglsters an electromagnetic looking for locking the movable from the register the register similar i'uunerical d which are prowith an impulse driving or motion or to send control and, in addition, device controlled switch arm of the selector in each posi' tion.

The maximum speed of such selectors is in a marked degree depcinlent upon the speed at which said he brought into operatu that the switching process locking device can in due to the fact by which the locking device is caused to operate comprises a seams of operations ot different snatching devices such as relays and clutch magnets which require a time for their operation. drive the selectors at a high of the above mentioned previously been proposed pulse sender of the sele ing device in relation to certain amount of To be able to speed in spite difficulties, it has to displace the imctor and the lockcach other in such a manner that said switching process is started already arm of the selector has settin position. i From said sender and the locking however, be too large.

take into account that th said switching process 1 cnt displacement between the for different switching before the movable switch attained the desired practical reasons impulse device must not, It is necessary to 0 time required for s somewhat difl'erdevices and,

further, thatthe speed of the selector may vary due to variations in the voltage of the current supply for of the selector. tioned variations in the of the switching devices and rather narrow limits of adjustment are obtained which to a certain do the selector gree put a limit to any ting speed of the select the driving mechanism Considering the above menspeed of operation the speed of rcase in the set.-

The object of the present invention is to eliminate said inconven ieucc.

The invention principally consists therein that the switching process by which the locking into operation is starte by which the register is position, but not com d evicc is brought d by that impulse set into the marked plated until a sue (feeding impulse is sent from the impulse sender of the selector before the selector has reached the desired setting position. It is thus possible to operate with a complete reliability having the impulse sender and the locking device displaced a distance corresponding" to as far as double the distance between adjaccnt setting positions of the selector. i

The invention will be more closely described with reference to the accompanying drawing which illustrates a circuit diagram in which only those parts of the selector and the register which concern the present invention are shown.

The impulse sender of the selector oomprises a bar IS connected to the movable switch arm and provided with teeth IT adapted to cooperate with a contact spring IK which is included in the impulse circuit leading to the register. A locking bar i locking bar in any setting position through it a detent SH adapted to be actuated from the register by means of an electro-magnet SM. i y y y y t The impulse register includes a numberof primary register switches in known manner receive impulses from the impulse sender of the subscriber or of the operatm' respectively, a contact arm not shown being then set to connect a contact in the correspondingcontact banks RK and v BK to a contact bar KS and KS respectively. The register also comprises a numher of secondary register switches IM IM which receive the impulses sent from the selectors through the medium of an impulse v relay IR; and which are provided with contact banks 1K and 1K respectively which are connected to the contact banks of the primary register switches in a certain inanner in order to obtain a translation to that numerical system aocori'ling towhich the contacts of the contact fieldsof the selectors aregrmiped. W In the example shown it assumed that the selector has 25 setting positions. In accordance herewith the second: ary register switch 1M is provided with 25 contacts which are connected to the contacts inthe primary registerswitch RS, as indicated on the drawing flndf tltlmblndd with R8,, RS which her else required.

three contact bars KS KS KS which are connected to the first three contacts in the switch RS In the present case the secondary register switches are assumed to be of that kind which are moved forward two steps for each impulse from the selector i. 0. one step at the closing and one step further at the interruption ot the current. The number of impulses required for the setting of the selector is thus reduced to the half and, consequently, the number of teeth IT on the in'ipulse bar IS is only half the num- The vertical lines 1, 2, State, which are drawn between the different locking teeth on the bar SS indicate the locking positions corres 'Jomling to the setting positions of the selector. These lines also indicate that the impulse bar IS and the locking bar SS are so displaced in relation to each other that the detent SH has not yet reached the first locking position in the movement when the impulse current is closed through the contact spring IK upon a displacement oi the bars in the direction of the arrows. Said locking position is not r arched until the free end of the contact spring has left the first tooth IT. The re sult aimed. at by said displacement of the impulse bar IS in relation to the locking bar SS may, of course, also be obtained by displacing the contact spring IK and the detcnt SH in a corresponding manner relatively each other.

The selector is adapted to be driven by machine power from a continuously rotating shaft to which the selector is coupled by means of an electro-magnetic clutch KM. The dii'lerent switching operations are controlled in a manner usual in machine driven systems i. e. by means of a control switch or a sequence switch of which only the contacts S0 S0 SQ required for the present purpose are shown. 7

The switching operation proceeds in, the following manner. After the register switches RS RS have been set. the sequence switch is actuated and the contacts SO S0, S0,, are thus closed.

A circuit 11 is then closed through the locking magnct SM which actuates the detent- SH and releases the switch arm of the selector and also the bars IS and SS secured. to the switch arm. At

the same time the detent SH closes at the contact K, a circuit 12 through the clut h magnet KM thus starting theselector. Simultaneously with the starting of the selector the magnet of the register switch IM is energized by a current impulse over a circuit 13, the register switch being thus advanced one step. During the movement of the selector the teeth on the impulse bar IS will actuate the contact spring 1K, an impulse circuit 14 being thus closed and opened alternately. lVhen said circuit is closed the impulse relay IR is actuated which then opens the circuit 13 for the regi:-1ter switch TM which is thus moved forward for another step. lVhen the contact spring IK has prsscd the first tooth the impulse circuit is interrruiteih the register switch .ltrl bring then moved forward another step. In this manner the operation proceeds, the register switch being advanced one step for rach closing and another step for each interruption of the impulse circuit, until said, switch reaches the contact bar marked by the register switch BS, and the contact marked by the switch RS It the impulse relay IR is then current carrying a circuit 15 is closed which includes a relay SR, which. is energized and connects itself into a holding circuit 16, the interruption of the circuit ll of the locking magnet SH being thus prepared. The last mentioned circuit remains. hmwwer still closed by another relay which is not actuated until the selector has passed the next impulse position in which. the impulse relay IR is tie-energized and closes a circuit 17 for the relay SR which in turn interru 'its the circuit 11 for the locking magnet SM. At the same time the register switch IM, is moved forward one step the circuit 17 being then opened. Already before then, however, the relay SB has obtained holding current orera circuit 18. The circuit 11 ot' the locking magnet- SM is therefore new definitely interrupted. The last. iDt'QIll'lPtlOll in the impulse circuit 1% occurred when the detent SII passed. or had ustpassed that setting osition which precedes the position in which the selector is required to stop. hen the detent SH is released it will thus lock the selector in the correct position. Upon being released it will in the first moment bear against the upper surface of the tooth on the lert't. hand. side of the lot-hing position. the circuit 12 thus remaining closed and the selector. ctmtinuing its movement till it has been centered in the position in question.

As will be urnlerstood from the t'tu'egoing description, the displacement between the iniipulse sender and the locking de ice is so adjusted that the selector after the sending of that imrmlse which brings the register in an operative position will have to pass a distance correspoinling to about double the distance between two adjacent contact. positions, before it is locked in the desired poi-4ition. Such large displacement has been made possible by dividing the switching PIOGL which brings the locking device into operation into the two phases which are controlled by two consecutive impulses from the selector, the locking being prepared by the first impulse and completed by the second.

I claim:

An arrangement in machine driven selectors of the kind which are set; under the control of a register or other similar numerical lltl switching apparatus and which for this purpose are provided with an impulse sender actuated by the IllQClltlIliSIllOf the selector for sending control impulses to the register, and an electromagnetic locking device actuated from the register for locking the movable switch arm of the selector in the set position, characterized by the impulse sender and the locking device being displaced in 10 relation to each other in such a manner that the switching process which brings the look ing device into operation is started by that impulse whereby the register is set into operative position and is completed by at succeeding impulse which is sent from the impulse sender, before the selector has reached the desired setting position.

In testimony whereof I afiix my signature.

HANS WILHELM ROBERT THORELLI. 

